debug: Log attribute differences in updateDocument

Temporary debug to identify cache vs DB data differences.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: abnegate

src/Database/Database.php

@@ -5701,6 +5701,7 @@ public function updateDocument(string $collection, string $id, Document $documen
                     // If values are not equal we need to update document.
                     if ($value !== $oldValue) {
                         $shouldUpdate = true;
+                        error_log("DEBUG shouldUpdate: key={$key} type_new=" . gettype($value) . " type_old=" . gettype($oldValue) . " val_new=" . json_encode($value) . " val_old=" . json_encode($oldValue));
                         break;
                     }
                 }